Introduction to convection fin type radiator
Currently finned convection radiator, the tube main use high-frequency welding finned tubes, brass and string aluminum, L-type fin tube
| aluminum extruded finned tubes. As the saying goes, I do not know whats not afraid, afraid of confinement. Now these types of finned tubes one by comparison.
First, high-frequency welding finned tube is on the pipe around the strip, while the winding side high frequency current welded together. Its advantage is low cost. Commonly used materials in the radiator, the steel should be the most expensive materials. Its disadvantages are: 1) high-frequency welding high power consumption, known as electric tiger. 2) general reach full welding, thermal contact resistance large. 3) limited by technology, high sheet generally not more than 15 mm, pieces from a larger cooling area is not big enough and therefore, the thermal efficiency is not high. 4) pipe and strip rust, when the heating pipes with plastic pipes, radiators waterways also with steel pipes, shame. Some producers have realized that this is a transitional product.
Second, brass string on the thin-walled copper tube aluminum is aluminum foil stamping on a string round or square aluminum plate, and then expanding technology, to eliminate the gap between copper and aluminum. The advantage is that aluminum can be made of any size, without limitation. Its disadvantages are: 1) The ratio of copper aluminum soft, no matter what kind of expanding technology, a combination of both can not be very tight, plus the expansion and contraction of the change, over time will produce loose, once loose, the thermal efficiency is greatly reduced. 2) aluminum foil is very soft, even if the pressure on the few bars, it can not change the nature of its weakness, touched on the back, not easy to clean. Professor Xiao Yuerong said: "durable and reliable, the first requirement corrosion products, other should also include strength and rigidity of these should be the first requirement for a lightweight radiator." Poor rigidity aluminum brass string, which is an undeniable fact, but many people in the evaluation of this product, almost forgot this. 3) manufacturers to reduce costs, brass is getting thin, brass does not corrode this is unrealistic, using brass air cooler on the industrial history has been very long, brass corrosion phenomenon is when occur. 4) production process more, production efficiency is not high.
Three, L-type sheet around the pipe or tube is wound into a copper tube with aluminum L-shaped fins. In industrial air cooler, L-type wound chip Tubing Compared with rolling fin, it belongs to the product being replaced. The reasons are: 1) combination is not tight, the contact pressure only rolling fifth finned tube when the tube wall temperature exceeds 70oC, L fin began to loosen, the contact resistance increases. 2) the fins with Aluminum (thickness 0.6㎜) wound, although the wound in tensile deformation, but not enough work hardening, the fin is relatively soft, touched on the back, poor reliability.
Fourth, rolling finned tube Advancement early in the 1940s stand out in the "heat exchanger" a book, to compare a variety of finned tubes, finned tube rolling many properties are ranked First, it is an alternative product L fin tube. Beijing Kyoto Spark Energy Saving Technology Development Co., Ltd. to develop a new generation of rolling finned tube forming machine, it can be rolled steel-aluminum, copper and aluminum composite, aluminum plastic composite, and aluminum four series of finned tubes, fin spacing 5.8 mm High film is not less than 22 mm, the fin trapezoidal cross-section, the top fin thickness 0.35 mm. Advantages rolled finned tubes are: 1) combination of very close contact pressure up 75㎏ / cm 2, and therefore changes in the thermal cycling conditions are never loose. 2) the fins are formed from aluminum extrusion cold, after cold hardening, rigid aluminum fins very good, durable and reliable. 3) high thermal efficiency. 4) When the base pipe with PEX or PB plastic pipes, tubes 50 years longevity radiator This is it. 5) The production process is simple, from raw materials to qualified products, once formed, they can produce 300 meters a day. In addition, production costs should be fairly and L-type finned tubes.
high-frequency welding finned tubes|brass and string aluminum| L-type fin tube| aluminum extruded finned tubes